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In order to receive benefits under SSA you must have worked the required number of quarters and put in money into the system or collect off of someone who has done so, such as you are collecting off of your father. Thus, if you were working and became disabled and had paid in a sufficient number of quarters into the SS system, you would be eligible for disability of that amount or more based on your contributions. However, if you have never worked under the SS system and are collecting under your father's rights, I am afraid that you would not be eligible for new benefits, but you can file with SSA to ask them to reevaluate the benefits you are receiving to determine if you are entitled to an increase based off your father's benefits.
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